5 replies to this topic

[kumarnagarathinam]

hello friends,


i got a problem in the feed details of three phase separator using hysys

how can give the feed details.

i have crude assay details, associated gas composition and water flowrate (nearly 85%).

can i use a mixer to combine all the three feeds or is there is any other way



kumar

[Padmakar Katre]

Dear,
If you charecterized the oil in the Oil Environment of the Simulation Basis Manager of Hysys then you will find the stream in your simulation PFD. This stream will have the compositions only and need to give the conditions like T , P and the Flowrate. So your crude stream will get converged and then you create another stream of water (for this stream you can give T,P Flow in the conditions tab and the composition tab put water molefraction as 1 ) and these 2 streams connect to the mixer you will be able to converge the mixer. Once you have converged the mixer just get the 3-phase separator from the object pallate and make the necessarry connection i.e. inlet (the mixer outlet stream which you have to connect to the separator inlet), Ovh vap/gas, Light Liquid and Heavy Liquid. The 3-phase separator in Hysys without an energy stream is an operation with 0 degrees of freedom so once you make the connections the separator will get converge.
If you don't have water as one of the components in your component list which you can easily find just by clicking on compostions tab of any stream then you enter into the basis environment and then add water as component.Then return to the simulation. I hope this should work. Waiting for your reply.

[kumarnagarathinam]

dear sir,

Thanks for your reply. I have little problem in doing so.
The well from which the feed is got is using a gas lift pump, ie they are injecting free natural gas to bring out oil.
so there will be natural gas dissolved in it + light ends of the original crude.

i have got pure crude composition (TBP without gas) + gas composition seperately.

so can i mix gas+ crude + oil in the mixer to prepare the feed.

waiting for your reply.


regards,

kumar.N

[Zauberberg]

Yes, that is the simplest way of combining streams. Make sure that crude is defined (and verified) within Oil Manager procedure, then simply install it by assigning stream name in the "Install Oil" tab. It will appear in the main flowsheet as a separate stream with the same name you have given to it.

Combine the streams at equal pressure and temperature levels in order to obtain correct parameters of combined stream. And don't forget to add produced/free water, even if it is not present in your production fluid (later you can simply decant it in 3-phase separator). Reservoir systems are usually saturated with H2O.

Regards,

[kumarnagarathinam]

Yes, that is the simplest way of combining streams. Make sure that crude is defined (and verified) within Oil Manager procedure, then simply install it by assigning stream name in the "Install Oil" tab. It will appear in the main flowsheet as a separate stream with the same name you have given to it.

Combine the streams at equal pressure and temperature levels in order to obtain correct parameters of combined stream. And don't forget to add produced/free water, even if it is not present in your production fluid (later you can simply decant it in 3-phase separator). Reservoir systems are usually saturated with H2O.

Regards,

Thanks a lot.

I will work out with your advice.

But still a small doubt. i have created the fluid package for crude using hypo component of peng robinson.

My problem is, can i use the same fluid package for gas and water also? or i have to include a separate peng robinson for gas & water?


kumar

[Zauberberg]

The answer is: yes, and it is highly recommended to do so. No reason to differentiate between crude oil and lift gas since they - basically - represent non-polar hydrocarbon mixtures. Peng-Robinson EOS should be used for all components.

For water saturation, you can use Kabadi-Danner package in the separate sub-flowsheet because it gives the highest values of equilibrium water in hydrocarbon cuts. This can be important if you are routing flash gas to downstream TEG/dehydration units. But, even if you use PR fluid package, the difference can be considered almost negligible. PR gives very good estimates of equilibrium water content in hydrocarbons.

Best regards,